If you're using body-parser as a body parsing middleware in Node.js application, you should take note of a serious security vulnerability (identified as CVE-2024-45590). Affected versions of body-parser prior to 1.20.3 are vulnerable to denial of service (DoS) attacks when URL encoding is enabled.

In this post, we're going to explore the nature of this vulnerability, discuss how a malicious actor could exploit it, and provide details on how to address this issue in your application.

Overview of body-parser

Body-parser is a popular npm package for handling incoming request bodies in a middleware before the handler is executed. It's widely used for parsing application/json, application/x-www-form-urlencoded, and multipart/form-data content types.

CVE-2024-45590 Details

This vulnerability arises when a malicious actor sends specially crafted payloads to the server in a large amount of requests. If your Node.js application is using a vulnerable version of body-parser with URL encoding enabled, it could be subjected to a denial of service (DoS) attack.

When body-parser first reads the request and encounters a URL-encoded payload, it generates a deeply nested structure that will consume large amounts of memory and CPU. As a result, the server may become unresponsive, and eventually, crash, rendering it inaccessible to legitimate users.

Here's an example of the possible code snippet in a Node.js application that's vulnerable to this attack:

const express = require('express');
const bodyParser = require('body-parser');
const app = express();

app.use(bodyParser.urlencoded({ extended: true }));

app.post('/submit_data', (req, res) => {
  // process data
});

app.listen(300, () => console.log('Server listening on port 300'));

In this example, the application uses body-parser to parse URL-encoded data with extended mode enabled. A malicious actor could send specially crafted payloads that would consume the server's resources and lead to a DoS attack.

The vulnerability has been documented in the following resources

- Original GitHub Security Advisory: GHSA-p8f9-7w4x-49ff
- CVE-2024-45590 on the NIST National Vulnerability Database
- The npm Security Advisory

To address this issue, upgrade body-parser to version 1.20.3 or later, which contains the patch that resolves the vulnerability. You can do this by running the following command:

npm install body-parser@^1.20.3 --save

After upgrading body-parser, make sure you update your application's dependencies and test it for compatibility. By taking these steps, you'll be protecting your application and its users from potential DoS attacks.

Conclusion

Security vulnerabilities such as CVE-2024-45590 highlight the importance of keeping Node.js middleware like body-parser up-to-date. By ensuring that version 1.20.3 or later is installed in your application and being vigilant about updates, you can help safeguard your server and users from potential denial of service attacks.

As always, it's a good practice to regularly audit your dependencies for vulnerabilities and update them as needed. It's an essential part of maintaining a secure and efficient web application.

Timeline

Published on: 09/10/2024 16:15:21 UTC
Last modified on: 09/20/2024 16:26:44 UTC